"Use The Force": From Photons To Lightsabers - And Beyond

Sounds like a scientifically inaccurate exaggeration, but according to scientists at Harvard and MIT, photons have been manipulated into actually binding together. Given that photons are universally regarded as having no mass, this seemed like an impossibility...until just recently.

"Most of the properties of light we know about originate from the fact that photons are massless, and that they do not interact with each other," Lukin said. "What we have done is create a special type of medium in which photons interact with each other so strongly that they begin to act as though they have mass, and they bind together to form molecules. This type of photonic bound state has been discussed theoretically for quite a while, but until now it hadn't been observed.

"It's not an in-apt analogy to compare this to light sabers," Lukin added. "When these photons interact with each other, they're pushing against and deflect each other. The physics of what's happening in these molecules is similar to what we see in the movies."

To get the normally-massless photons to bind to each other, Lukin and colleagues, including Harvard post-doctoral fellow Ofer Fisterberg, former Harvard doctoral student Alexey Gorshkov and MIT graduate students Thibault Peyronel and Qiu Liang couldn't rely on something like the Force – they instead turned to a set of more extreme conditions.

Researchers began by pumped rubidium atoms into a vacuum chamber, then used lasers to cool the cloud of atoms to just a few degrees above absolute zero. Using extremely weak laser pulses, they then fired single photons into the cloud of atoms.

As the photons enter the cloud of cold atoms, Lukin said, its energy excites atoms along its path, causing the photon to slow dramatically. As the photon moves through the cloud, that energy is handed off from atom to atom, and eventually exits the cloud with the photon.

"When the photon exits the medium, its identity is preserved," Lukin said. "It's the same effect we see with refraction of light in a water glass. The light enters the water, it hands off part of its energy to the medium, and inside it exists as light and matter coupled together, but when it exits, it's still light. The process that takes place is the same it's just a bit more extreme – the light is slowed considerably, and a lot more energy is given away than during refraction."

When Lukin and colleagues fired two photons into the cloud, they were surprised to see them exit together, as a single molecule.

I find this lack of logic...confusing. Interstellar cinematic puns aside, let's see exactly how this was possible not and not before. Because believe it or not, there is a reason.

An effect called a Rydberg blockade, Lukin said, which states that when an atom is excited, nearby atoms cannot be excited to the same degree. In practice, the effect means that as two photons enter the atomic cloud, the first excites an atom, but must move forward before the second photon can excite nearby atoms.

The result, he said, is that the two photons push and pull each other through the cloud as their energy is handed off from one atom to the next.

"It's a photonic interaction that's mediated by the atomic interaction," Lukin said. "That makes these two photons behave like a molecule, and when they exit the medium they're much more likely to do so together than as single photons."

While the effect is unusual, it does have some practical applications as well.

Practical applications start with quantum computing and expand to include optical routers and crystalline structures. Apparently, geeks expecting lightsabers set the bar rather low in anticipation of this development. This isn't just a movie experience come to life - it's a revolution of data processing and energy manipulation.

Whadaya guys think?

Source

Silly me, I didn't check to see if this had been posted yet. Turns out it's a few hours late. Bless those early birds. Mods, do what you gotta do.

In the event that ATS authorities decide to close this thread rather then delete it, here's a link to the one that was posted much earlier today. Discussion can be continued there:

www.abovetopsecret.com...

Already posted but your title is better.

Scientists Create Never-Before-Seen Form of Matter

reply to post by soficrow


You must have missed my previous post in this thread, and thanks.